Herpes simplex virus type I (HSV-1) is a common human pathogen causing cold sores, and in rare cases, severe keratitis and encephalitis. Mouse models are commonly used to study HSV pathogenesis, but mice are not a natural host for this virus. Therefore, it is important to have comprehensive knowledge of the cross-species differences between mice and humans to understand the limitations of these models. As the first evidence of the extent of difference, we found that HSV-1 produced more infectious virus in primary human compared with primary mouse fibroblasts over a multi-step infection. Next, a cross-species RNA-seq approach was used to find host gene signatures that might explain this difference in virus titers. Strikingly, mouse cells up-regulated more genes in an antiviral pathway characterized by interferon (IFN)-stimulated genes (ISG). Among genes mapped in this pathway, Janus kinase 1 (Jak1) and myxovirus-resistance genes (Mx1) were located at the center of a functional gene network so that we examined their involvement in the human-mouse difference. Jak1 is an essential component of IFN signaling to trigger antiviral responses and thereby, modulates the transcription of numerous ISGs. Mx1, is an antiviral effector that is non-functional in the mouse strain used here, but can act as a read out for ISGs. Using CRISPR knockout, we found that Jak1 played a crucial role to reduce virus growth in mouse cells. Further, the use of virus mutants showed that HSV-1 UL41 (vhs), but not, UL54 (ICP27), was required to observe differences in Jak1 levels and virus replication between human and mouse cells. Taken together, these observations suggest a model where HSV-1 UL41 mediates species-specific immune evasion via regulation of Jak1 and therefore ISGs in human, but not mouse cells.